Hydrophobic modification conditions of Al2O3 ceramic membrane and application in seawater desalination

1H,1H,2H,2H-perfluorodecytriethoxysilane (C16H19F17O3Si) be successfully applied to the hydrophobic modification of Al2O3 tubular ceramic membrane. Taking the concentration of modification solution, modification time, and modification temperature as factors, orthogonal experiments were designed to study the hydrophobicity of the composite membranes. The experiments showed that the modification time had the greatest impact on the experimental results, followed by the modification temperature, and the modification solution concentration had the smallest impact. Concentration of the modified solution 0.012 mol·L-1, modification temperature 30°C and modification time 24 h were considered optimal hydrophobic modification conditions. And the pure water flux reached 274.80 kg·m-2·h-1 at 0.1MPa before hydrophobic modification, whereas the modified membrane completely blocked liquid water permeation at pressures less than 0.1MPa. Air gap membrane distillation experiments were conducted for NaCl (2wt%) solution, and the maximum flux reached 4.20 kg·m-2·h-1, while the retention rate remained above 99.8%. Given the scarcity of freshwater resources in coastal areas, the article proposed a system for seawater desalination using air conditioning waste heat, and conducted preliminary research on its freshwater production performance using Aspen Plus. Finally, the proposed system achieved a freshwater production capacity of 0.61 kg·m-2·h-1.